If your after the best power, you need a custom CAI that sits behind the bumper with a velocity stack. Its what my TopFuel kit will be getting replaced with.
It won't be easy, or cheap, or for those who are paranoid about hydrolocking but it will make the most power.
AEM and Ingen both do CAI's, make good power, probably the same as if not more than the Tegiwa kit, but same issue with hydrolocking paranoia.
Tegiwa is a good off the shelf solution, its safe and makes good power, and sounds good too, its proven, however the fit might leave you wondering from what I gather.